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<title>DD API Usage</title>
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<h2>The Examples of DD API Usage.</h2>
<h3>Example 1</h3>

In this example, DD API client prints all listener classes from  deployment descriptor to console:<br>
<p>
<pre>
<div class="nonnormative">
<font class="keyword">package</font> mypackage;

<font class="keyword">import</font> org.netbeans.api.web.dd.DDProvider;
<font class="keyword">import</font> org.netbeans.api.web.dd.WebApp;
<font class="keyword">import</font> org.netbeans.api.web.dd.Listener;
<font class="keyword">import</font> org.openide.filesystems.*;

<font class="keyword">public class</font> <b>ListenerExample</b> {
<font class="comment">
    /**
     * @param args the command line arguments
     */
</font>
   <font class="keyword">public static void</font> main(String[] args)<font class="keyword">throws</font> <b>Exception</b> {

	<font class="comment">// get the file object of web.xml file</font>
        <b>DDProvider</b> ddProvider = DDProvider.getDefault();
        <b>FileObject</b> fo = <b>Repository</b>.getDefault().findResource("<font color="constant">WEB-INF/web.xml</font>");

	<font class="comment">// get the deployment descriptor root object</font>
        <b>WebApp</b> webApp = ddProvider.getDDRoot(fo);

	<font class="comment">// print the version of deployment dscriptor</font>
        System.out.println("<font color="constant">DD version = </font>"+webApp.getVersion());

	<font class="comment">// get the array of listeners and print the listener classes</font>
        <b>Listener</b> [] listeners = webApp.getListener();
        <font class="keyword">for</font> (int i=<font color="constant">0</font>; i&lt;listeners.length; i++) {
            System.out.println("<font color="constant">Listener [</font>"+i+"<font color="constant">] = </font>"+listeners[i].getListenerClass());
        }
   }
}
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</pre>
</p>

<h3>Example 2</h3>

In this example, DD API client searches a servlet "CarServlet" and, if such a servlet exists, 2 init parameters are created : "car_type" and "car_color".<br>
Then, finally, changes ara saved back to file object :<br>
<div class="nonnormative">
<pre>
 <font class="keyword">package</font> mypackage;

 <font class="keyword">import</font> org.netbeans.api.web.dd.DDProvider;
 <font class="keyword">import</font> org.netbeans.api.web.dd.WebApp;
 <font class="keyword">import</font> org.netbeans.api.web.dd.Servlet;
 <font class="keyword">import</font> org.netbeans.api.web.dd.InitParam;
 <font class="keyword">import</font> org.openide.filesystems.*;

 <font class="keyword">public class</font> <b>InitParamExample</b> {
 <font class="comment">    
    /**
     * @param args the command line arguments
     */
</font>
    <font class="keyword">public static void</font> main(String[] args) <font class="keyword">throws</font> <b>Exception</b> {

	<font class="comment">// get the file object of web.xml file</font>
        <b>DDProvider</b> ddProvider = DDProvider.getDefault();
        <b>FileObject</b> fo = Repository.getDefault().findResource("<font class="constant">WEB-INF/web.xml</font>");

	<font class="comment">// get the deployment descriptor root object</font>
        <b>WebApp</b> webApp = ddProvider.getDDRoot(fo);

	<font class="comment">// print the version of deployment dscriptor</font>
        System.out.println("<font class="constant">DD version = </font>"+webApp.getVersion());

	<font class="comment">// looks for the "CarServlet" servlet at WebApp object by ServletName property</font>
        <b>Servlet</b> servlet = (Servlet) webApp.findBeanByName("<font class="constant">Servlet</font>", "<font class="constant">ServletName</font>", "<font class="constant">CarServlet</font>");

        if (servlet!=<font class="constant">null</font>) {

            <font class="comment">// add the first InitParam object to Servlet object</font>
            servlet.addBean("<font class="constant">InitParam</font>", new String[]{"<font class="constant">ParamName</font>","<font class="constant">ParamValue</font>"}, new String[]{"<font class="constant">car_type</font>","<font class="constant">FORD</font>"}, <font class="constant">null</font> );

            <font class="comment">// add the second InitParam object to Servlet object</font>
            servlet.addBean("<font class="constant">InitParam</font>", new String[]{"<font class="constant">ParamName</font>","<font class="constant">ParamValue</font>"}, new String[]{"<font class="constant">car_color</font>","<font class="constant">green</font>"}, <font class="constant">null</font> );

	    <font class="comment">// print all init params to console</font>
            <b>InitParam</b> [] newParams = servlet.getInitParam();
            <font class="keyword">for</font> (int i=<font class="constant">0</font>;i&lt;newParams.length;i++)
                System.out.println("<font class="constant">init-param [</font>"+i+"<font class="constant">] = </font>"+newParams[i].getParamName()+"<font class="constant"> -&gt; </font>"+newParams[i].getParamValue());

	    <font class="comment">// write changes back to file object</font>
            webApp.write(fo);
        }
    }
 }
</pre>
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